Pull-out guide

ABSTRACT

A pull-out guide for domestic appliances. The pull-out guide includes a guide rail, at least one additional rail displaceably mounted relative to the guide rail via a rolling body in a rolling-body cage, and at least one stop configured to limit a displacement path of the at least one additional rail. The at least one stop is configured as a first crosspiece and shaped onto one of the guide rail and the at least one additional rail. The at least one stop projects into the displacement path of one of the rolling-body cage and the rolling body. The rolling body is an outer rolling body. The at least one stop projects up to at least half of the radius of the outer rolling body or up to substantially a rotational axis of the outer rolling body, as seen in a direction of displacement.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a national stage of International ApplicationPCT/EP2011/064244, filed Aug. 18, 2011, and claims benefit of andpriority to German Patent Application No. 10 2010 037 097.5, filed Aug.20, 2010, the content of which Applications are incorporated byreference herein.

BACKGROUND SUMMARY

The present invention relates to a pull-out guide for domesticappliances. The pull-out guide includes a guide rail, at least oneadditional rail displaceably mounted relative to the guide rail via arolling body in a rolling-body cage, and at least one stop configured tolimit a displacement path of the at least one additional rail. The atleast one stop is configured as a first crosspiece and shaped onto oneof the guide rail and the at least one additional rail.

Such pull-out guides are known in numerous embodiments from the state ofthe art. They frequently consist of a guide rail and at least onerunning rail. The running rail is displaceably held relative to theguide rail via rolling bodies which are accommodated in rolling-bodycages. Pull-out guides are also known comprising a guide rail, a runningrail and an interposed middle rail. The guide rail is displaceably heldin relation to the middle rail via rolling bodies accommodated inrolling-body cages, and with the middle rail also being displaceablyheld relative to the running rail via rolling bodies accommodated in arolling-body cage.

The paths of displacement of the individual rails with respect to oneanother are precisely defined. These paths in the individual componentsare usually configured in such a way depending on the pull-out path, thelength of the spherical cages or the rolling-body cages and the raillength that path limits provided on the rails will be accessedsimultaneously. A displacement of the rolling-body cages or sphericalcages between the respective two rails may occur by certain externalcircumstances during transport of the pull-out guides as a result ofvibrations or an unfavourable transport position in the package or alsoas a result of the presence of a large quantity of lubricant forlubricating the rolling bodies under simultaneous loading of the rails.This leads to the consequence that the rolling-body cage or sphericalcage is prematurely moved to one of the stops. This offset may become solarge that the pull-out guides cannot be opened and closed completely,or only with a major input of force. In order to produce the fullrunning range of the pull-out guides again, the pull-out guide needs tobe stretched, that is, it is pulled or pushed under application of forceto its end position. In this process, the rolling bodies need to slidein a certain region because they are unable to reach the end position bymere rolling off.

Such stops for defining the running ranges of the rails, with respect toeach other, are arranged on a rail in such a way that they will pressthe rolling bodies against the track of the opposite rail and thereforeproduce a wedging effect. This wedging effect leads to a high level ofsliding friction, which again leads to a respectively high stretchingforce that needs to be applied. In the event of a simultaneouslyoccurring lack of lubrication, this wedging effect may even lead tocomplete blockage of the pull-out guide. Such a lack of lubricationfrequently occurs in pull-out guides which are subject to extremeenvironmental conditions. Examples for such conditions are baking ovens,pyrolysis ovens or dishwashers.

Embodiments of the present disclosure provide for a pull-out guide whichcan be pushed back or pulled back to its original state after adisplacement of a rolling-body cage or a spherical cage with a lowamount of stretching force and especially without any blockage.

Thus, an embodiment according to the present disclosure includes apull-out guide for domestic appliances. The pull-out guide includes aguide rail, at least one additional rail displaceably mounted relativeto the guide rail via a rolling body in a rolling-body cage, and atleast one stop configured to limit a displacement path of the at leastone additional rail. The at least one stop is configured as a firstcrosspiece and shaped onto one of the guide rail and the at least oneadditional rail. The at least one stop projects into the displacementpath of one of the rolling-body cage and the rolling body, the rollingbody being an outer rolling body. The at least one stop projects up toat least half of the radius of the outer rolling body or up tosubstantially a rotational axis of the outer rolling body, as seen in adirection of displacement.

In accordance with an embodiment of the present disclosure, the at leastone stop for limiting the path of displacement of the at least oneadditional rail is arranged as a cross piece which is shaped on theguide rail or on the at least one additional rail and projects into thepath of displacement of the rolling-body cage or of an outer rollingbody, as seen in the direction of displacement. The crosspiece projectsclose to the rotational axis, for example, up to at least half theradius of the rolling body. As a result of the attack of the crosspieceon the rolling-body cage, the likelihood of blockage of one of therolling bodies is excluded from the outset. If the crosspiece engages onat least half the height of the radius, for example, close to therotational axis of the rolling body on the rolling body, this will notproduce a force component perpendicular to the displacement direction,or only a very low such force, so that the rolling body will not besubject to any likelihood of being pressed from the plane of thedisplacement direction against one of the running surfaces of the rails.

Embodiments according to the present disclosure are discussed herein andin the appended claims.

According to an embodiment of the present disclosure, the crosspiece isarranged as a bridge shaped transversely to the direction ofdisplacement and interacting in function with the rolling-body cage.From a production standpoint, such a bridge can be shaped very easily ina rail from the outside.

In accordance with another embodiment of the present disclosure, thepull-out guide includes at least one crosspiece which is arranged as abridge shaped transversely to the direction of displacement andinteracting in function with the rolling-body cage. In addition, afurther crosspiece protrudes up to and close to the rotational axis, forexample, up to the rotational axis of the rolling bodies. This furthercrosspiece interacts with a rolling body which is on the outside as seenin the direction of displacement. The combination of the two crosspieceembodiments allows an exceptionally reliable limitation of the runningpath.

In accordance with another embodiment of the present disclosure, theguide rail and the at least one additional rail include several runningsurfaces extending parallel with respect to one another for several rowsof rolling bodies. The several rows of rolling bodies are arranged inthe rolling-body cage parallel with respect to each other in the runningdirection. The crosspieces protrude into the path of displacement of therolling-body cage and are shaped from a first running surface of one ofthe guide rails or one of the additional rails, and the crosspiecesprotruding into the path of displacement of the rolling bodies areshaped on one of the other guide rails parallel to the first runningsurface or an additional rail. This ensures that the crosspieces used asthe running or displacement path limit will not collide with each otherduring the displacement of the rails relative to one another.

Other aspects of the present disclosure will become apparent from thefollowing descriptions when considered in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded side view of an embodiment of a pull-out guide,in accordance with the present disclosure.

FIG. 2 shows a side view of the pull-out guide of FIG. 1 in theassembled state.

FIG. 3 shows a top view from the front of the pull-out guide of FIG. 1and FIG. 2.

FIG. 4 shows a side view of the pull-out guide of the FIGS. 1 and 2without showing the guide and running rail.

FIG. 5 shows a front view of the middle rail and the rolling bodiesarranged around the middle rail of FIG. 4 without showing therolling-body cage.

FIG. 6 shows a perspective exploded view of a further embodiment of apull-out guide in accordance with the present disclosure.

FIG. 7 shows a perspective view of the middle rail of the pull-out guideof FIG. 6 and showing the rolling bodies and the rolling-body cagesarranged around the middle rail.

FIGS. 8 to 10 show different views of a rolling-body cage of thepull-out guide in accordance with the present disclosure.

FIGS. 11 to 14 show front views of different embodiments of guide railsand running rails with rolling bodies arranged therein and differentlyarranged crosspieces, in accordance with the present disclosure.

FIG. 15 shows a top view from the front of an alternative embodiment ofthe pull-out guide of FIG. 1 and FIG. 2, in accordance with the presentdisclosure.

FIG. 16 shows a front view of the middle rail of the pull-out guide ofFIG. 15 and the rolling bodies arranged around the middle rail withoutshowing the rolling-body cage.

DETAILED DESCRIPTION

In the description below, the terms such as above, below, left, right,front, and rear, for example, relate exclusively to the exemplaryillustrations shown and position of the pull-out guide and other partsas shown in the respective drawings. These terms shall not be understoodas being limiting in any way, which means such references can change inaccordance with different working positions or mirror-symmetricalconfigurations, for example.

FIGS. 1 and 6 show embodiments of a pull-out guide, in accordance withthe present disclosure, which pull-out guides are designated withreference numeral 1. The pull-out guide 1 comprises a guide rail 4 whichcan, for example, be fixed to a side wall of a domestic appliance suchas a baking oven, a pyrolysis oven, a dishwasher, a piece of furnitureor any other component such as, for example, a side grating in a cookingdevice. A middle rail 3 may be displaceably mounted on guide rail 4 viarolling bodies 6. A running rail 2 may be displaceably mounted in thesame manner on the middle rail 3 via further rolling bodies 6. Therolling bodies 6 are held on the rolling-body cages 5 in a mannercombined into packets.

As is shown in FIGS. 1 and 6, crosspieces 21, 32, 41 are shaped into oneof the respective rails, that is, on one or more of the guide rail 4,the middle rail 3 and the running rail 2. The crosspieces 21, 32, 41 areused as stops for fixing the running ranges or paths of displacement ofone or more of the individual rails 2, 3, 4, relative to one another.The crosspieces 21, 41 are shaped inwardly from the outside into theguide rail 4 and into the running rail 2, and may be, for example,arranged as a bridge which extends into the path of displacement, ordisplacement path, of the rolling-body cage 5. In the embodiment, asshown in FIG. 3, the crosspieces 21, 41, which are arranged as a bridge,are respectively shaped into a corner region of the guide rail 4 and therunning rail 2. This is so that rolling-body cage 5, which isdisplaceable along the inside of the guide rail 4 and the running rail 2in the direction of displacement x, can only be moved in a reciprocatingfashion within the region between the two crosspieces 21, 41.

The crosspiece 21, 41 of the guide rail 2 and the running rail 2, whichis arranged as a bridge, extends diagonally between two adjacent sidewalls of the guide rail 4 and the running rail 2 and impinges, infunction, on a face side of the rolling-body cage 5 displaceable withinthe guide rail 4 and the running rail 2.

The crosspieces 32 arranged on the middle rail 3 may be, for example,shaped in the manner of a cylinder. The cylindrical shape of thecrosspiece 32 is provided in such a way that a face side of the cylinderis used as a stop surface for a rolling body 6, which is on the outsideas seen in the direction of displacement x, and which is displaceablyarranged on the outside on the middle rail 3 in a track of the middlerail 3. The crosspieces 32 extend up to at least half the radius of therolling body 6 into the path of displacement of the rolling bodies 6 inorder to prevent the rolling body 6 from being pressed out of the planeof the displacement direction x against one of the running surfaces ofone of the rails 2, 3, 4. The maximum length of the crosspieces 32 islimited by the track of the oppositely disposed running rail 2 andmiddle rail 4, on which the crosspiece 32 must not impinge.

As is shown in FIG. 3, the embodiment of the pull-out guide 1. inaccordance with the present disclosure comprises both at least onecrosspiece 21, 41 which is arranged as a bridge shaped transversely tothe direction of displacement x and interacts in function with therolling-body cage 5, and also one further crosspiece 32 interacting withthe rolling body 6 and protruding at least up to half of the radius ofthe rolling body 6.

In order to prevent a collision of the crosspieces 21, 32, 41 in thiscombination of the crosspieces 21, 32, 41, the crosspieces 21, 32, 41are arranged on the guide rail 4, the middle rail 3 and the running rail2 in such a way that they extend in, respectively, different runningparts in which the rolling bodies 6 are arranged behind one another inthe direction of displacement x.

In addition to the arrangement of the crosspieces 21, 41, which areshown in FIG. 3 and are arranged as bridges and correspond with the facesides of the rolling-body cages 5 in function, further or alternativepossibilities for arrangement of the crosspieces 21, 41 are within thescope of the present disclosure, and may be as shown in FIGS. 12 to 14.In the embodiment as shown in FIG. 12, one respective further crosspiece21, 41 is provided in the guide rail 4 and the running rail 2, whichcrosspiece 21, 41 does not extend diagonally between two adjacent sidewalls of the guide rail 4 or the running rail 2 as a bridge, but as acrosspiece which extends into the guide rail 4 or the running rail 2 andwhich protrudes inwardly from one of the side walls of the guide rail 4or the running rail 2.

As is shown in FIGS. 8 to 10, the rolling-body cages 5 in which therolling bodies 6 are held, are shaped in such a way that several rows ofrolling bodies 6 arranged in parallel with respect to each other can beheld in rolling-body receiving openings 52. Caps 53, which may, forexample, be respectively shaped in a triangular fashion, extend forguiding the rolling bodies 6 on the rolling-body receiving openings 52on the edges extending transversely to the direction of displacement x.In order to enable direct contact of the crosspieces 32 shaped out ofthe middle rail 3 with an outer rolling body 6, as seen in the directionof displacement x of the rolling-body cage 5, the rolling-body receivingopenings 52 arranged at the end of one of the running rows of therolling bodies 6 are provided with such a cap 53 only on the edge facingthe middle as seen in the longitudinal direction of the rolling-bodycage 5. Accordingly, the edge of the outermost rolling-body receivingopening 52, facing away from the middle of the rolling-body cage 5 isfree from such a cap 53, so that the rolling body 6 guided therein cancome into direct contact with a crosspiece 32 during approach to thecrosspiece.

The rolling bodies 6 may, for example, be arranged as rolling-bodyballs. An arrangement of the rolling bodies in a cylindrical shape isalso within the scope of the present disclosure.

FIG. 4 shows a middle rail with rolling-body cages 5 arranged thereonwith rolling bodies 6 guided therein. The rolling-body cages 5 are shownin a position directly before a stop situation with the crosspieces 32disposed at the same height as the shaped portions 31.

FIG. 5 shows the middle rail 3 of FIG. 4 in a front view and withoutillustration of the rolling-body cages 5. FIG. 5 shows the crosspieces32, which are outwardly shaped from the middle rail 3, and whichrespectively protrude into a running path of the rolling bodies 6. Theshaped portions 31 may be, for example, arranged integrally with thecrosspieces 32.

FIGS. 15 and 16 show a further embodiment of the shaping of the shapedportions 31, in accordance with the present disclosure. The shapedportions 31 do not extend, in this embodiment, diagonally relative tothe cross section of the middle rail, but are bent off from the crosssection. This shaping of the shaped portions 31 can be introduced in anespecially careful manner into the running paths of the rolling body 6by deformation, especially by pressing in the running path, all inaccordance with the present disclosure.

Although the present disclosure has been described and illustrated indetail, it is to be clearly understood that this is done by way ofillustration and example only and is not to be taken by way oflimitation. The scope of the present disclosure is to be limited only bythe terms of the appended claims.

We claim:
 1. A pull-out guide for domestic appliances, the pull-outguide comprising: a guide rail; at least one additional raildisplaceably mounted relative to the guide rail via a rolling body in arolling-body cage; and at least one stop configured to limit adisplacement path of the at least one additional rail; the at least onestop configured as a first crosspiece and shaped onto one of the guiderail and the at least one additional rail; the at least one stopprojecting into the displacement path of one of the rolling-body cageand the rolling body, the rolling body being an outer rolling body; andthe at least one stop projecting up to at least half of the radius ofthe outer rolling body as seen in a direction of displacement; whereinthe first crosspiece is arranged as a bridge shaped transversely to thedirection of displacement and interacts with the rolling-body cage. 2.The pull-out guide according to claim 1, wherein the first crosspiece isarranged as a bridge shaped transversely to the direction ofdisplacement and interacts with the rolling-body cage, and a secondcrosspiece interacts with the outer rolling body and projects at leastup to half the radius of the rolling body.
 3. The pull-out guideaccording to claim 1, wherein the first crosspiece is arranged as abridge that extends diagonally between two adjacent side walls of one ofthe guide rail and the at least one additional rail, and the first crosspiece impinges on a face side of the rolling-body cage.
 4. The pull-outguide according to claim 1,wherein the first crosspiece projecting intothe displacement path of the rolling body is shaped in a cylindrical wayand includes a face side configured as a stop surface.
 5. The pull-outguide according to claim 1, wherein the first crosspiece is arranged asa bridge is shaped out of the guide rail and the at least one additionalrail is configured as a running rail, and a second crosspiece protrudesinto the displacement path of the rolling body and the second crosspieceis shaped on the at least one additional rail that is configured as amiddle rail.
 6. The pull-out guide according to claim 1, wherein therolling-body cage includes inwardly facing caps which are arrangedbehind one another on edges of rolling-body receiving openings in thedirection of displacement, with the caps disposed at an outermostposition in the direction of displacement being spared.
 7. The pull-outguide according to claim 1, wherein the guide rail and the at least oneadditional rail include running surfaces extending parallel with respectto one another and configured to accommodate several rows of rollingbodies which are arranged in the rolling-body cage parallel with respectto each other in the displacement direction, and the first crosspieceprotruding into the displacement path of the rolling-body cage is shapedout of a first of the running surfaces of the guide rail and the atleast one additional rail, and the first crosspiece protruding into thepath of displacement of the rolling bodies is shaped out of one of theguide rail parallel to the first of the running surfaces and the atleast one additional rail.
 8. A pull-out guide for domestic appliances,the pull-out guide comprising: a guide rail; at least one additionalrail displaceably mounted relative to the guide rail via a rolling bodyin a rolling-body cage; and at least one stop configured to limit adisplacement path of the at least one additional rail; the at least onestop configured as a first crosspiece and shaped onto one of the guiderail and the at least one additional rail; the at least one stopprojecting into the displacement path of one of the rolling-body cageand the rolling body, the rolling body being an outer rolling body; andthe at least one stop projecting up to substantially a rotational axisof the outer rolling body as seen in a direction of displacement;wherein the first crosspiece is arranged as a bridge shaped transverselyto the direction of displacement and interacts with the rolling-bodycage.
 9. The pull-out guide according to claim 8, wherein a secondcrosspiece interacts with the outer rolling body.